Targeting The Lipogenic Enzyme ATP Citrate Lyase As A Potential Therapy Against Coronary Artery Disease

Introduction: Coronary artery disease (CAD) such as coronary stenosis and intra vein graft stenosis are characterized by a cancer-like pro-proliferative and apoptosis-resistant phenotype of smooth muscle cells (SMCs), fueled by a metabolic shift toward glycolysis and interconnected global changes in the epigenetic landscape. The nucleo-cytoplasmic enzyme ATP Citrate Lyase (ACLY) has recently emerged as a key player and therapeutic target in cancer by favoring Warburg effect, lipid synthesis and chromatin remodeling. However, its role in CAD is still unknown. We hypothesized that ACLY is upregulated in CAD and supports the abnormal phenotype of CAD-CoASMCs. Methods and Results: ACLY expression positively correlates with vascular remodeling (aSMA labeling) in human distal coronary artery (CoAs, p<0,01) as well as in dog saphenous vein (SV) graft from bypass surgery (p<0,05). Increased expression and activation (phosphorylation) of ACLY were also observed in CoASMCs isolated from CAD patients (immunoblot, p<0,01) with preferential localization in the nucleus (immunofluorescence ACLY labelling (p<0,001)). Pharmacological (BMS303141) or molecular (siRNA) ACLY inhibition resulted in decreased survival, proliferation (immunoblot: PCNA, MCM2 and SURVIVIN (p<0,05) & immunofluorescence Ki67 and Annexin V labelling (p<0,001)), histones acetylation (immunoblot: acH3K27 and acH4 (p<0,05)) and reversed Warburg effect (immunoblot: pPDH, LDHA, PFKBP3 (p<0,01) & seahorse assays (p<0,05)) of CAD-CoASMC. RNA sequencing analysis showed that ACLY molecular inhibition in CAD-CoASMC mostly affectes cell cycle and cell proliferation pathways. Ex-vivo, ACLY inhibition attenuates vascular remodeling (EVG staining) in human CoAs and SVs rings denuded of endothelial cells and exposed to growth factors (p<0,05). In vivo, SMS-targeted loss of Acly in mice model of carotid artery denudation injury prevents vascular remodeling (p<0,05). Same results are observed with pharmacological inhibition of ACLY (BMS303141 & bempedoic acid) in carotid artery wire injury rat model (p<0,05). Conclusion: We demonstrated that ACLY is implicated in vascular remodeling in CAD and its Pharmacological inhibition may represent a novel avenue as therapeutic treatment.